ST1100 Flaky Neutral Light

[Uncle Phil]

One of the girls has a flaky neutral light - sometimes it works and sometimes it doesn't.
It seems to be the worse when the engine has been run for a while.
Do you think it is the neutral switch or the bulb going flaky?

 

[kiltman]

I’m gonna remain neutral as best as I can about flaky girls……

 

[afrymoyer]

Hey Phil...

I just did one this week on a '94 ABS. Crap connection at the neutral switch. I had to remove the gas tank to get at the neutral switch, due to the alternator, engine block and swing arm being in the way(there is no other way). I wire brushed the switch pin and dielectric pasted. I took one of my round brass wire brushes and cleaned out the connector and sprayed Fluid Film up inside it. I then "re-crimped" the round female bullet connector for a nice tight fit on the switch. I also did the oil psi sender while I was in there. Took a little over an hour...

 

[jfheath]

But neutral switch is the most likely. Find the connector and by-pass the switch - the switch merely connects/disconnects the wire to earth, so if earthing the wire / leaving it disconnected stops the lamp from flickering, then the problem is with the switch. If it continues flickering then the problem is elsewhere.

Neutral switch, clutch lever switch, side stand switch can all affect the neutral light depending on circumstances.

If the neutral switch doesn't fix the problem, It may be worth taking out the 3 legged diode from the wiring harness near your left knee and checking the blades and the contacts for slight corrosion. Don't do this with the ignition on though.

 

[Uncle Phil]

And where is that pesky little bugger?
I thought it was beside the alternator and you could get to it after you pull the fuel tank.
I found it - anybody remember the socket size it takes to get it out?
I can't seem to figure that one out - 14, 15?

 

[Uncle Phil]

Hey Phil...

I just did one this week on a '94 ABS. Crap connection at the neutral switch. I had to remove the gas tank to get at the neutral switch, due to the alternator, engine block and swing arm being in the way(there is no other way). I wire brushed the switch pin and dielectric pasted. I took one of my round brass wire brushes and cleaned out the connector and sprayed Fluid Film up inside it. I then "re-crimped" the round female bullet connector for a nice tight fit on the switch. I also did the oil psi sender while I was in there. Took a little over an hour...

Socket size to get the switch out?

 

[Uncle Phil]

Never mind - I finally figure it out.
For any poor soul that has to do this -
It takes a 'deep' 14mm socket - most standard ones are too short because of the connector on the end.
And you can get to it with some long extensions if you remove the lower gray panel on the frame.

 

[dwalby]

I found it - anybody remember the socket size it takes to get it out?
I can't seem to figure that one out - 14, 15?

I believe the Japanese typically use sizes like 8/10/12/14/17/19/22 so you'll never find a 15mm on one of their vehicles. And I see on your later post it was in fact a 14mm, which isn't surprising.

 

[Erdoc48]

So I assume the approach is from underneath the bike?

 

[Uncle Phil]

Not much point in diagnosis - the terminal had a nice green patina on it.
Took one off a parts bike, cleaned it up nice and shiny and all is well.
But putting that thing back in was a royal pain in the anatomy - especially if you have big hands!

 

[Uncle Phil]

So I assume the approach is from underneath the bike?

Nope, got to pull the gas tank to get to it.

 

[Chris09]

yeah I'm not gonna say much about nice girls and flakey neutrals either... must have been a Freudian slip, but..
I did get that with my '85 XL a couple years ago; the neutral remains illuminated, just started the bike last week and still does it, everything works well, wonder if it's got to do with the shifter position.

 

[Uncle Phil]

yeah I'm not gonna say much about nice girls and flakey neutrals either... must have been a Freudian slip, but..
I did get that with my '85 XL a couple years ago; the neutral remains illuminated, just started the bike last week and still does it, everything works well, wonder if it's got to do with the shifter position.

The way the ST1100 neutral switch works is there is a 'plunger' inside the case that evidently get pressed when in neutral.
The original would have probably worked but I had already cleaned up a replacement so I put it in.